Launcher using a vaporing liquid as a projectile propelling means



March 4, 1969 a. SILVER ETAL LAUNCHER USING A VAPORING LIQUID AS A PROJEC'IILE PROPELLING MEANS I Sheet Filed April 22, 1965 D a mask YQWQSGR INVENTORS.

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BERNARD SILVER CH/P/ST/AN C. BOLT/4 X Q 27%:

ATTORNEY United States Patent 3,430,619 LAUNCHER USING A VAPORING LIQUID AS A PROJECTILE PROPELLING MEANS Bernard Silver and Christian C. Bolta, Alexandria, Va.,

assignors to The Susquehanna Corporation, a corporation of Delaware Filed Apr. 22, 1965, Ser. No. 449,999 US. Cl. 124--11 26 Claims Int. Cl. F41b 11/06; F41c 1/04; F17e 9/02 ABSTRACT OF THE DISCLOSURE A launcher for propelling a projectile, comprising a housing for receiving the projectile and a closed container communicating with the interior of the housing and enclosing a liquid having a boiling point at ambient pressure below the ambient temperature. Suitable means are provided for selectively opening the container to rapidly expose a substantial surface of the liquid to the housing interior, thereby effecting flashing of the liquid to rapidly produce a pressurized vapor for ejecting the projectile from the housing.

This invention relates to launchers and, more particularly, to launchers actuated by vapor generated from easily volatilized fluids.

There is a present need for launchers capable of projecting item(s) a distance which may vary from a few miles to a few feet. Existing devices, ranging from rapidburning propellant type launchers to pressurized container dispensers, have many disadvantages which are overcome by the present invention.

Commencing with a brief discussion of long-range launchers, such as the rapid-burning propellant type, it is found that most such launchers are energized by highburning-rate propellants. It is undesirable to employ a system which is inherently dangerous as is such a system, especially when considering nonmilitary use or, in other words, civilian use. The nature of this energizing source greatly complicates the transportation, storage and operation of such a launcher. Furthermore, because of the extremely high peak pressures and temperatures to which such a launcher is exposed, it must be designed to withstand these conditions, which increases the weight and cost of the launcher many fold over what is required by the actual operating conditions necessary for launching. In addition, upon firing an explosive-actuated launcher both light and noise are generated thus providing a signature which may be undesirable in specific instances, for example, during wartime.

With reference to short-range dispensing, there are many such dispensers currently available; however, each with specific limitations or disadvantages. Use of mechanical dispensers of the type employing biasing means such as springs, is limited due to the size and weight of the mechanical devices used for providing the dispensing action. Fluid-actuated dispensers employ pressurized gas made available by either a compresesd gas reservoir or an easily volatilized liquid. Compressed gas systems, such as air or carbon dioxide systems, require a heavy-wall container to Store high pressure gas which increases the weight and the cost of the dispenser. Similarly, efifective sealing means must be used becaue 0f the high pressure differential existing across the seal. The liquid system simply requires a sealed liquid container for storing the liquid and its vapor. The liquid employed vaporizes at temperatures below the ambient temperatures Where the dispenser is used, e.g., around -20" F. and, therefore, the liquid will vaporize until the pressure in the container is equal to the vapor pressure at prevailing ambient temperatures at which time a liquid-vapor equilibrium will 3,430,619 Patented Mar. 4, 1969 ice exist. This pressure is relatively low, for example, about 100 p.s.i.a. An example of such a dispenser may be seen in US. Patent 2,925,937Schmidt et al. (1960).

Present day dispensers employing easily volatilized liquids are all designed for slow vaporizaion of the liquid in order to smoothly and slowly dispense a material such as a second liquid or a semisolid enclosesd within the dispenser. In order to achieve the smooth and constant dispensing of the material, a constant pressure is exerted against the material to be dispensed. This constant pressure is achieved in a nonadiabatic, isothermal, isobaric system where heat from the surrounding atmosphere and from the hand holding the dispenser necessarily is transmitted constantly to the vaporizing liquid thus continuously vaporizing the liquid and producing a constant pressure against the material to be dispensed. Such a heat transfer to provide a constant pressure is effective because the dispensing takes place over an extended period of time. Furthermore, the liquid or semisolid to be dispensed is forced through a constriction such as a valve which restricts the velocity and quantity of the dispensed material to relatively low values, thus preventing free flow of the stored material from the dispenser. Because of this restriction in flow and velocity and because of the heat transfer to the liquid through the dispenser, the pressure within the dispenser remains constant. Thus, such dispensers are specifically designed to avoid ejecting the material at high velocity for an extended distance.

The only device which employs a flashing fluid or rapidly volatilized fluid for ejecting solid material for an extended distance is the steam gun which was publicized around the turn of the century. Steam guns require a substantial water supply and hence a substantial reservoir, a boiler and a heat source to boil the water contained within the boiler. Valving means, such as a burst disc, is employed to allow the pressure within the boiler to increase thus permitting superheating of the water and steam. The valve means is so designed that on the attainment of a predetermined pressure within the boiler, the valve opens and the steam is permitted to act upon the projectile to be ejected. The disadvantages of such a system are ob vious. To begin with, a large supply of Water must be constantly available. A boiler is required to contain the water and a heat source to boil the water must also be available. This system is nonadiabatic and requires continuous energy input. Accurate determination of the instant of firing the steam gun is diflicult and the time between loading and firing is quite long. Examples of steam guns may be seen in Patents 441,676Lovegrove (1890) and 556,058-Huey (1896).

Birefly stated, the launcher of this invention, in one form, comprises a relatively thin-walled, hollow, cylindrical tube and a container housing a liquid which vaporizes at temperatures below the ambient temperatures at ambient pressure where the launcher is designed to be used. An example of such a liquid is dischlorodiiluoromethane (Freon 12), which has a boiling point of 2l.7 F. at atmospheric pressure. The can is sealed closed and at atmospheric tempertaures of around F. the vapor pressure within the can, when the liquid and vapor are in equilibrium, is approximately p.s.i.a. The can is placed at one end of the cylindrical tube and the projectile to be launched is located within the tube immediately adjacent to one end of the container. Means are provided to instantaneousl expose a substantial portion of the liquid surface to the conditions inside the cylindrical tube through a large orifice. This can be done by means of numerous container opening devices such as a removable plug, a puncturing device, etc.

When the liquid is exposed to the ambient conditions within the cylindrical tube, the pressure within the container is reduced and the superheated liquid flashes t0 vapor in an isentropic, adiabatic process. The vapor, which is generated without the transfer of energy into or out of the system, acts upon the projectile which is serving as a piston and causes it to move the length of the tube and to be ejected outwardly therefrom. The tube is designed so as to permit substantially unrestrained acceleration of the projectile during the launching operation. The entire launching process involves a time increment .in the order of milliseconds as compared with the above-referred-to dispensers which require a dispensing time normally exceeding a second.

Accordingly, it is one object of the present invention to provide a launcher which is inherently safe to store, transport, and use.

It is another object of this invention, to provide a launcher which is light in weight, portable, easily assembled, and inexpensive to manufacture.

A further object of this invention is to provide a launcher which does not require an energy input in order to energize the actuating means.

A still further object of this invention is to provide a launcher which is signature-free in that it is relatively silent and does not produce a flash of light.

Other objects and attendant advantages will become apparent from the following description and drawings wherein like reference characters designate corresponding parts throughout the several figures and in which:

FIGURE 1 is a temperature-entropy phase diagram generally depicting the phenomenon occurring during operation of the launcher of this invention,

FIGURE 2. is a pressure-time curve generally illustrating the pressure conditions during operation of the launcher,

FIGURE 3 is a sectional view of a launcher formed in accordance with a first embodiment of this invention,

FIGURE 4 is a view taken along line 44 of FIG- URE 3,

FIGURE 5 is a sectional view of a launcher formed in accordance with a second embodiment of this invention,

FIGURE 6 is a view taken along line 66 of FIG- URE 5,

FIGURE 7 is a sectional view of a launcher formed in accordance with a third embodiment of this invention,

FIGURE 8 is a view taken along line 88 of FIG- URE 7,

FIGURE 9 is a perspective view of the cutter and spider employed in the third embodiment,

FIGURE 10 is a sectional view of a launcher formed in accordance with a fourth embodiment of this invention,

FIGURE ll is a sectional view of a launcher formed in accordance with a fifth embodiment of this invention,

FIGURE 12 is a sectional view of a portion of the launcher of FIGURE 11 showing a modification comprising remote control operating means.

Basic concept The launcher of this invention is based upon the principle that a rapid decrease in the pressure on the surface of a liquid below the saturation pressure effects rapid volatilization or boiling of the liquid which occurs in such a short period of time that the liquid flashes into a vapor. The vapor, which is made available, is utilized to per form work. More specifically, a liquid which is enclosed within a sealed container evaporates until the vapor pressure is equal to the saturation pressure corresponding to the temperature of the liquid. At this point liquid-vapor equilibrium exists within the container. Flashing of a portion of the remaining liquid in the container can be produced by rapidly opening the container and reducing the pressure on the surface of the liquid. The liquid temperature will then be above the boiling point for the surface pressure available and the liquid will immediately flash into vapor. The choice of liquid is determined by the climes where the launcher use is intended so that the liquid has a boiling point below the ambient temperature range for ambient pressure conditions. The above system 4 'l provides a vapor having a pressure in excess of the ambient pressure and, therefore, provides a source of power which is available for launching matter. For example, dichlorodifluoromethane (Freon 12) has a boiling point of 21.7 F. at atmospheric pressure (14.7 p.s.i.a.). Freon l2, enclosed within a sealed container at a temperature of R, will vaporize until the vapor pressure within the container is equal to the saturation pressure which, for the liquid mentioned, is approximately p.s.i.a. By instantaneously exposing the liquid to atmospheric pressure the pressure within the container drops and a portion of the remaining liquid flashes to vapor which exits from the container and is utilized to perform work. It can, for example, move a piston located within a tube over a finite distance and, if desired, eject the piston or matter behind the piston, from the tube.

To more easily understand the physical phenomena occurring during the launching operation, reference is made to FIGURE 1 which is a general temperature-entropy phase diagram for any conventional substance, and to FIGURE 2 which is a pressure-time diagram illustrating the pressure changes within the liquid container (solid line) and on the high pressure side of the piston (dotted line).

During the period in which the liquid is stored within the container, the liquid temperature is equal to the ambient temperature T and the saturation pressure within the container is indicated as p which is greater than atmospheric pressure 2 The liquid vapor saturation conditions are shown at point A. The pressure in the tube immediately adjacent to the container is atmospheric pressure (p Upon opening the container to the restricted volume formed by the tube and the piston referred to above, the pressure in the container instantaneously decreases adiabatically and isentropically because no energy is transferred into or out of the system. Because of the reduced pressure in the container a portion of the liquid instantaneously vaporizes or flashes thus producing additional vapor. Vaporization occursby removing heat from the remaining liquid causing the liquid bulk temperature to decrease (see point B). The quantity of liquid which vaporizes depends upon the initial temperature T and the ratio of the volume into which the vapor expands and the volume of the liquid. The vaporization and liquid temperature decrease continues until the pressure in the container is at equilibrium with the pressure in the tube or, if the piston is allowed to leave the tube, until the pressure in the container is equal to atmospheric pressure as shown at point C. The solid-line curve in FIGURE 2 illustrates the pressure drop in the container over the time interval during launching, which is very short.

The above describes the the occurrences within the container. Turning now to the varying conditions on the face of the piston within the tube, refer to the dottedline pressure-time curve of FIGURE 2. Initially, at time t the pressure on the face of the piston is atmospheric (12 as is shown at point D. Immediately after the container is opened, the pressure on the face of the piston rises rapidly. The piston, free to slide within the tube, concurrently travels at an accelerating rate down the length of the tube because the force on the piston produced by the pressure of the vapor acting against the piston exceeds the sum of the forces produced by the atmospheric pressure acting against the piston and any frictional force which exists between the piston and tube walls. Because the piston is traveling away from the container, the volume in the tube to which the vapor is expanding is also increasing at an increasing rate. Shortly after the container is opened a point will be reached where the vapor enters the tube at a rate which is less than the rate of volume increase in the tube into which it expands, and at this point the pressure begins to decrease (point E). It should be noted that the mass flow rate from the container to the tube is limited by the pres sure and temperature conditions within the container,

the pressure in the tube, and by the size of the orifice from which the vapor is passing into the tube. Maximum flow rate occurs when the flow through the orifice is equal to sonic velocity or, in other words, when the pressure ratio across the orifice is equal to or less than the critical pressure ratio.

The piston will continue to accelerate down the length of the tube until it is ejected from the tube at which time the pressure on the face of the piston is equal to atmospheric pressure (point P). The vapor continues'to exhaust from the container and, immediately after the piston is ejected from the tube, pressure equilibrium between the container and the tube is reached at atmospheric pressure illustrated as point C. It should be noted that the curve of FIGURE 2 is for a launcher designed for maximum efiiciency where the pressure on the piston face equals atmospheric pressure at the instant of ejection from the tube. If the pressure on the piston face exceeds atmospheric pressure when the piston reaches the end of the tube, there would be a discontinuity in the curve showing a rapid pressure drop.

Because there are many controllable variables, such as tube length, gas pressure, orifice size, etc., the desired launch conditions of exit velocity or launch distance for a given mass of matter to be launched can be accurately controlled and varied within wide limits. Three basic formulas employed for calculating the required values are as follows:

(1) force equation p n where:

m =mass of piston u =velocity of piston A =area of piston face p=pressure on piston face (2) vapor mass balance equation where:

m =mass of vapor V =volume of tube between piston and container density of vapor (3) flow equation where:

A =area of container orifice C =orifice coeflicient p =pressure in container p pressure in tube adjacent to orifice By fixing certain of these values, the remaining values can be established. To begin with, the choosing of a specific liquid establishes the vapor density and vapor pressure within the container for specific temperatures. Similarly, the piston area and mass can either be fixed, in which case the other values may be established or they may be the values to be determined by predetermining the desired velocity of the piston after a predetermined length of time. The required pressure can be minimized by increasing the length of the tube thus increasing the time during which the piston accelerates. Which values are to be fixed and which are to be calculated depends upon the particular application.

The various embodiments to be hereinafter described, all rely upon a rapidly flashing liquid to provide a source of pressurized gas in an extremely short period of time, for example, milliseconds, which is then utilized to launch whatever matter is intended to be launched. It will be seen that the embodiments described hereinafter are merely examples of various ways in which this invention can be employed and should not be interpreted as limiting the scope of this invention to the specific structure illustrated and described.

First embodiment (FIGURES 3 and 4) Reverting now to the drawings, and more particularly to FIGURES 3 and 4, there is shown a first embodiment of this invention which comprises launcher 8 including a housing 10, a container 12, and container opening means, generally shown at 14, for rapidly exposing a substantial portion of the inside of the container to the interior of the housing 10. These three elemnets, i.e., the housing 10, the container 12, and the container opening means 14, comprise the essential elements of the launcher S of this invention.

The housing 10 is an alongated tubular member which serves jointly as a housing for the container 12 and the container opening means 14, and as a launching tube, illustrated as portion 16 of the housing 10. The launching tube section of the housing permits substantially unrestrained acceleration of the matter to be launched (not shown) through the tube. Because the pressure required to launch the desired matter for the desired distance can be maintained relatively low, the housing 10 can be fabricated of a thin-walled light-weight tubing, for example, metals such as aluminum or magnesium; plastics such as polyvinyl chloride; glass fiber; or compressed paper board.

The container 12 for storing the liquid can be of any shape or size and, because the vapor pressure which the container 12 will be required to contain will be relatively low, the container 12 can also be fabricated as a thinwalled, light-weight container. One end 18 of the container is provided with a neck 20 having a port 21 through which the liquid is loaded into the container 12 and through which the generated vapor exhausts. In order to expose the maximum surface of the liquid within the container 12 to the interior of the housing 10, and to permit maximum flow of the generated vapor through the port 21, it is desirable to provide the port 21 with as large a diameter as possible. After the liquid (not shown) is loaded into the container 12, the container is sealed by means of a plug 22 having one or more O-rings 24 around the periphery thereof in order to ensure proper sealing of the container 12. The plug 22 is provided on its foremost or exterior surface or end 26 with a projection 28 having a serrated portion 30 for reasons described below.

The container is partially filled with a liquid having a boiling point at ambient pressure substantially below the ambient temperature. The term ambient is used here and throughout this specification to mean atmospheric conditions at the time and in the climes where the launcher is used. Another prerequisite of the liquid and vapor is that they be compatible with the launcher elements they contact. Examples of suitable liquids along with certain critical data are:

An extraction means or piston 32 is slideably mounted Within the housing 10 and has provided on the surface thereof adjacent to the container 12 a hollow cylindrical extension 34. The extension 34 is sized to receive the serrated projection 30. The projection 30 is serrated to permit the extension 34 to slip over it with relative ease and yet provide sufiicient resistance to removal of the projec tion 30 from the extension 34 to permit the plug 22 to be removed from the orifice 21 when the piston 32 is forced in a direction away from the container 12.

The container 12 and the piston 32 are loaded into the housing 10 on opposite sides of an annular shoulder 36 which extends inwardly from the inner surface of the housing 10. The piston is forced towards the container 12 to cause the serrated portion 30 to mate with the extension 34. A helical spring 38 is provided between the piston 32 and the shoulder 36 in order to normally bias the piston in the direction away from the container 12. A removable pin 40 is inserted through a hole 42 in the housing wall in order to retain the piston in a loaded position in which the spring 38 is in a compressed condition. The container 12 is held in place by any conventional means, for example, a plug 43 which is externally threaded and received by internal threading 44 on the interior surface of the housing 10 at one end thereof.

After the container 12 and piston 32 are loaded into the housing 10, the matter to be propelled or launched (not shown) is then loaded into the launching section 16 of the housing 10 to abut against or be in close proximity to the piston 32. The matter to be launched can be in the form of a solid, a semisolid, or a liquid since any of these forms can be ejected from the housing 10 by means of a rapidly moving piston 32.

Operation is commenced by extracting the pin 40 from the housing 10. The spring 38 forces the piston 32 to move away from the container 12, and in so moving, removes the plug 22 from the orifice 21 of the container 12. As soon as the plug 22 is removed, the pressure within the container 12 rapidly decreases approaching the atmospheric pressure conditions within the housing 10. As soon as the pressure within the container decreases the liquid rapidly vaporizes or flashes to produce additional vapor having a pressure equal to the saturation pressure of the liquid at the liquids temperature, which is approximately equal to the ambient temperature. The generated vapor exhausts through the port 21 and acts upon the piston 32 causing the piston to accelerate rapidly and substantially unrestrained throughout the legnth of the housing 10 and launching the matter which was contained within the launching section 16 of the housing 10. Because the piston 32 was given initial motion by the spring 38, the vapor need not overcome the static friction and, therefore, the required pressure to achieve the desired velocity of the piston can be maintained at a minimum. As explained earlier, the entire flashing and launching operation occurs within a time interval in the order of milliseconds. The matter to be launched or propelled and the piston 32 are not restricted in any form from moving as rapidly as the vapor acting upon the piston will cause them to move. The entire process is adiabatic and isena tropic since no external source of energy is required to vaporize the liquid. The process is not isobaric because the pressure within the housing 10 and container 12 decreases with time, as is shown in FIGURE 2.

Second embodiment (FIGURES 5 and 6) A second embodiment is illustrated in FIGURES 5 and 6. The launcher 50 of the second embodiment includes a housing 52 having a launching section 54 and a container 56 having a neck portion 58. Fitted within the neck 58 is a plug 60 attached at one end to a spider 62. The spider 62 includes an annular ring 63 and a plurality of diametrical support strips 64 defining a plurality of flow points 65. The plug 60 is fitted within the neck 58 such that it prevents escape of the vapor from within the container 56 but, at the same time, can be easily removed from the neck 58. To augment the sealing of the plug 60 an O-ring 66 can be placed between the plug and the container neck 58. The container-spider assembly is placed inside the housing 52 and the spider 62 is held in place by any removable means such as a pin 67. An annular groove 68 is provided on the peripheral surface of the spider to receive the pin 67 thus locking the spider 62 in place. The container 56 is held in place adjacent the spider 62 by means of a plug 70 having a longitudinal groove 71 in the outer surface thereof. The groove 71 at a point furthest from the container 56, ends with a further recessed portion 72. The housing 52 is provided with a radial hole 74 coaxial with the recessed portion 72 when the plug 70 is in place in the housing 52. The plug 70 is held in place by a pin 76 extending through the hole 74 and into the recessed portion 72.

When it is desired to launch the matter to be ejected, the pin 76 is retracted from the recessed portion 72 and the plug is forced rearwardly a distance greater than the depth of insertion of the plug 60 inside the container neck 58. By retracting the pin 76 the vapor, which exerts a force against the container rear wall 77 which has a larger surface area than the surface area of the container front wall 78, causes the container 56 to move rearwardly, as shown by the dotted lines in FIGURE 5. Because the plug 60 is not fixedly mounted within the neck 58 but is only tight enough to adequately seal the container 56, and because the plug is afiixed to the spider 62 which is restrained from movement by the pin 67, the plug 60 will be extracted from the neck 58 permitting the vapor to exhaust from the container 56, flow through the spider 62 and act upon the matter to be ejected (not shown). During rearward movement of the plug 70 the pin 76 slides within the groove 71 until the pin abuts the end 79 of the groove, thus preventing further rearward movement without removal of the pin 76.

The first two embodiments described above employ a removable plug for exposing the liquid to the launcher housing interior. The following embodiments employ a means for cutting or piercing the can to expose the liquid.

Third embodiment (FIGURES 7-9) The launcher 80 of the third embodiment of this invention, illustrated in FIGURES 7-9, includes a housing 82 having an elongated launch section 84. A sealed liquid container 86 is held within one end of the housing 82 by means of a resilient clip 88. The housing 82 is provided on its outer surface with an indentation 90 to receive the clip 88 and prevent the clip from sliding off the housing. The container is closed or sealed in any conventional manner. One example of such a closure, illustrated in FIGURE 7, comprises crimping a cap 92 onto the open end of the container 86. A gasket 93 is located between the cap 92 and the container 86 to provide the required sealing.

An annular shoulder 94 is located on the inner surface of the housing 82 to provide an abutting surface for a helical spring 95 which is located on the side of the shoulder 94 facing the container 86. Mounted in the housing 82 between the spring 95 and container 86 is a spider 96 on which is attached an annular cutter blade 98. The spider 96 includes an annular ring 100 and a plurality of diametral support strips 102. The blade 98 is mounted on the support strips 102 either by being formed integrally therewith or by being attached thereto by any conventional method, such as welding.

The blade 98 has a trapezoidal, longitudinal crosssection as can be seen in FIGURE 7 such that one portion of the cutter 98 is in close proximity to the container cap 92 while the remainder of the blade 98 tapers away therefrom. The blade 98 has a cutting edge 104 which extends approximately 340 around the cutter leaving only a small portion 106 which is located furthest from the container cap 92 without a cutting edge. The outer surface of the blade 98 is provided with a land 108 immediately adjacent the portion 106 for a purpose described below.

The blade-spider combination is mounted in the housing 82 in a manner as to compress the spring 95 against the shoulder 94 and is held in this position by a pin 109 which extends through an opening 110 in the housing 82. When the pin 109 is extracted from the housing 82 the spring 95 causes the spider 96 and blade 98 to move rapidly towards the container 86 and forces the blade 98 to pierce the container cap 92. The cap is not pierced in a complete circle but, instead, remains attached to the container 86 by a thin strip provided by the blade portion 106 which is absent a cutting edge. After the blade has pierced the cap 92 the land 108 forces the cut flap 112 to bend inwardly, as shown by the dotted lines in FIGURE 7, thus opening the container 86 and eliminating obstruction to vapor flow through the orifice formed by the cutting operation just described. The vapor leaving the container 86 passes through the orifice, through the spider 96, and acts upon the matter to be launched (not shown). If desired, a piston 114 can be employed on which the vapor acts and which serves as a working surface to force the matter to be launched out of the launching section 84 of the housing 82.

Fourth embodiment (FIGURE Another modification or a fourth embodiment of this invention is illustrated by the launcher 120 as shown in FIGURE 10 which includes a housing 122 having a launch section 124 and an annular shoulder 126 on the inner surface of the housing 122. A liquid container 128 is held in place on one side of the shoulder 126 and spaced therefrom by an annular spacer 129 and by means of a threaded plug 130. A piston 132 is provided on the other side of the shoulder 126. The modification of this embodiment resides in the means for opening the container 128. This means includes a conventional linear-shaped charge 134, for example, pentaerythrite tetranitrate (PETN) en cased in a shaped metal sheath, which is held in place around the outer edge of the container cap 136. A detonator 138 is attached to the linear-shaped charge 134 and ignition means, for example, electrical wires 140, extend from the detonator to the outside of the housing 122 through a sealed port 142. The detonator 138 is actuated by an electrical impulse provided from a conventional electric source (not shown). The explosive power of the linear-shaped charge 134 is sized just large enough to pierce or sever the container cap 136 and permit free flow of the vapor from the container 128. However, if desired, the charge can be sized slightly larger than is required to pierce the container cap and the additional energy from the charge can be used to increase the vaporization rate of the fluid and, therefore, the pressure within the container 128. Additionally, because of the nature of the cutting means, it is possible to provide an exhaust port having a minimum cross-sectional area.

Fifth embodiment (FIGURE 11) FIGURE 11 illustrates a launcher 150 which forms the fifth embodiment of this invention. The launcher 150' includes a housing 152 having a launching section 154. A spider 156 is fixedly held within the housing 152 by snap rings 157, 158, which are received by annular grooves 159, 160, respectively, in the inner surface of the housing 152. The spider 156 has an extension 161 projecting from the face thereof remote from the launching section 154. The liquid (not shown) is stored within an elongated container 162. The container 162 is fitted with a depending cap 163 crimped in sealing relationship onto the forward end of the container. A gasket 164 is placed between the cap and container to provide the required sealing. The cap 163 extends downwardly within the container 162 for a portion of the containers legnth and is hollow for reception of the projection 161. An O-ring 165 is mounted on the outer periphery of the projection 161 and held in place by a pair of annular extensions 166, 168. The O-ring sealingly engages the sides of the depending cap 163, as may be seen in FIGURE 11.

The cap 163 is provided with a line of weakness such as an annular groove 170 inscribed therein adjacent the lowermost end thereof to permit relatively easy separation of the caps lower portion 172 from the remainder of the cap and container when the cap is placed in tension by a method described below.

The container 162 is forced onto the projection 161 by a loading mechanism 174 which includes a tubular slide 176 having a wall 178 on one end thereof. The wall 178 includes a threaded bore 180 axially therethrough. A piston 182 having an externally threaded shaft 184 is threadably engaged in the wall 178 such that the piston 182 is on the outside thereof. The end of the shaft 184 remote from the piston 182 is provided with a slot 186 sized to receive a tool such as a screw driver (not shown.) Rotation of the tool engaged within the slot 186 causes the piston 182 to move toward or away from the wall 178.

The container 162 is fed into the rearward end of the housing 152 and forced toward and onto the projection 161 by the loading mechanism 174. The loading mechanism is advanced into the housing 152 to a predetermined position where it is retained by a removable pin 188 inserted through a hole 190 in the housing 152 and received by a groove 192 in the periphery of the slide 17 6, the groove 192 having a further recessed portion 193 at the end thereof remote from the wall 178. A tool is then inserted in the slot 186 and rotated to cause the piston 1 82 to translate away from the end wall 178 until it abuts the container 162. Continued translation of the piston 182 causes the container 162 to slide onto the projection 161 until the cap 1 6-3 abuts the lowermost end of the projection 161. Continued force on the container 162 places the cap 163 in increasing tension until the cap 163 fails along the line of weakness 170. The caps lower portion 172 will then fall inside the container 162 as shown by the dotted lines in FIGURE 11. The vapor, however, will remain contained because the projection 161, by means of the O-ring 165, maintains the container in a sealed condition.

When it is desired to eject the matter to be launched, the pin 188 is retracted from the recessed portion 193 and the slide 176 is free to move rapidly rearward,.the pin 188 sliding in the groove 192. This permits the container 162 to travel rearwardly due to the vapor pressure inside the container acting upon the container rear wall 194 until the cap 163 slides beyond the projection 161, the projection being held in place by the rings 157, 158. When the cap 163 is free of the projection 161, the interior of the container 162 is exposed to atmospheric conditions Within the housing 152 thus causing the liquid to rapidly vaporize. The vapor passes through the spider 156 and acts upon the matter to be launched in the same manner described above.

Any and all of the above-described embodiments can be remotely operated by conventional mechaniwl, electrical, or electromagnetic means. For example, it is ob vious that the electrical source for actuating the detonator 138 (FIGURE 10) of the fourth embodiment can be located remote from the launcher 120. Similarly, the pins 40 (FIGURE 3), 76 (FIGURE 5), 109 (FIGURE 7), and 188 (FIGURE 11), of the first, second, third, and fifth embodiments, respectively, can be moved by conventional solenoid means located remote from the launchers, as shown schematically in FIGURE 12, which particularly relates to the fifth embodiment. FIGURE 12, illustrates a solenoid coil 196 surrounding the pin 18 8, which is made of a ferromagnetic material, the coil being in circuit with any conventional solenoid current supply 198. A passage of current through the coil 196 generates a magnetic flux which retracts the pin 188 thus permitting operation of the launcher 150.

It can be seen from the discussion of the -five embodiments described above that a launcher has been taught which is inherently safe to store, transport and use because the pressurized gas employed is of relatively low pressure and is supplied by vaporization of a harmless liquid, rather than an explosive. Furthermore, because the pressure required is maintained low, the launcher housing and liquid container can be light-weight and the entire launcher is easily assembled and inexpensive to manufacture. The entire unit and requirements are selfcontained and there is no requirement of an external energy input to vaporize the liquid.

It should be obvious that the particular embodiments and specific structures described above are merely examples of various types of launchers embodying the general principles of this invention and should not be considered as limiting the scope of this invention to the embodiments specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. Launching means for propelling a projectile, comprising:

(a) a housing means adapted to receive said projectile and permit substantially unrestrained acceleration thereof,

(b) a container having a port and a closure means in sealing relationship with said port effecting closure of said container, said port being of a size to expose a substantial portion of the interior of said container and being in communication with the interior of said housing means,

(c) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature, and

(d) container opening means for rapidly removing said closure means from said port to expose a substantial surface of said liquid to the interior of said housing means to effect flashing of said liquid and thereby to rapidly produce a pressurized vapor for rapidly ejecting said projectile from said housing means.

2. Launching means for propelling a projectile, comprising:

(a) a housing adapted to receive said projectile and permit substantially unrestrained acceleration thereof,

(b) a container having a large port, said port being in communication with the interior of said housing,

() a plug mounted in sealing relationship with said port to effect closure of said container, said plug having a projection extending outwardly therefrom,

(d) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature,

(e) :a piston slideably mounted within said housing, said piston having an extension which engages said projection,

(f) biasing means normally urging said piston in a direction to remove said plug from said port, and

(g) locking means holding said piston in a first position wherein said plug is in sealing relationship with said port, release of said locking means permitting said biasing means to move said piston into a second position elfecting removal of said plug from said port exposing a substantial surface of said liquid to the interior of said housing to effect flashing of said liquid and thereby to rapidly produce a pressurized vapor for rapidly ejecting said projectile from said housing.

3. Launching means as defined in claim 2 wherein said housing is an elongated cylindrical tube.

4. In combination, a projectile having a predetermined external shape and size, and launching means for propelling said projectile, said launching means comprising:

(a) a housing with a cross sectional dimension substantially the same as that of said projectile for receiving said projectile and permitting substantially unrestrained acceleration thereof,

(b) closure means fixedly mounted within said housing,

(c) a container having a large port, said container being releasably mounted adjacent said closure means such that said port is obturated by said closure means when said container is in a first position and said port is open for fluid flow therethrough from said container into said housing when said container is in a second position,

(d) locking means for holding said container in said first position,

(e) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature, and

(f) means for moving said container from said first position to said second position upon release of said locking means to rapidly expose a substantial surface of said liquid to the interior of said housing to effect flashing of said liquid and, thereby, to rapidly produce a pressurized vapor for rapidly, ejecting said projectile from said housing.

5. The combination as defined in claim 4 wherein said means for moving said container comprises pressure of the vapor sealed within said container, release of said locking means permitting said pressure to force said container away from said closure means into said second position.

6. The combination as defined in claim 4 wherein said closure means comprises an annular member and a plug fixedly attached thereto.

7. The combination as defined in claim 4 wherein said closure means comprises:

(a) an annular member,

(b) a support member extending inwardly from said annular member, and

(c) a plug fixedly attached to said support member,

said plug, said annular member, and said support member defining at least one fluid flow port and wherein said housing comprises an elongated cylindrical tube.

8. In combination, a projectile having a predetermined external shape and size, and launching means for propelling said projectile, said launching means comprising:

(a) a housing with a cross sectional dimension substantially the same as that of said projectile for receiving said projectile and permitting substantially unre strained acceleration thereof,

(b) a closed container having one wall thereof communicating with the interior of said housing,

(0) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature, and

(d) container opening means for rapidly severing said one wall to rapidly expose a substantial surface of said liquid to the interior of said housing to eflfect flashing of said liquid and, thereby, to rapidly produce a pressurized vapor for rapidly ejecting said projectile from said housing.

9. The combination as defined in claim 8 wherein said container opening means comprises a cutter blade fixedly mounted on a support member, biasing means urging said support member in a direction toward said one Wall and locking means holding said blade in a first position wherein said blade is spaced from said one wall; upon release of said locking means, said biasing means effects rapid movement of said blade to a second position wherein said blade pierces said one wall.

10. Launching means as defined in claim 9 wherein said blade in said second position extends through said one wall along a line which defines a flap attached at one point to said one wall.

11. Launching means as defined in claim 10 wherein said blade includes means for bending said flap into said container.

12. Launching means as defined in claim 9 wherein said blade in said second position extends through said one wall along a line which defines a flap completely severed from said one wall.

13. Launching means as defined in claim 9 wherein said blade has a trapezoidal, longitudinal cross-section such that the cutting surface of said blade recedes from said one wall when said blade is in said first position.

14. Launching means as defined in claim 8 wherein said container opening means comprises an explosive charge attached to said one wall and means for igniting said charge.

15. Launching means as defined in claim 14 wherein said charge is a linear-shaped charge arranged in a substantially circular configuration on said one wall.

16. In combination, a projectile having a predetermined external shape and size, and launching means for propelling said projectile, said launching means comprising:

(a) a housing with a cross sectional dimensionsubstantially the same as that of said projectile for receiving said projectile and permitting substantially unrestrained acceleration thereof,

(b) a closed container communicating with the interior of said housing, said container having a line of weakness formed therein,

(c) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature, and

((1) container opening means for effecting structural failure of said container along said line of weakness to rapidly expose a substantial surface of said liquid to the interior of said housing to effect flashing of said liquid and, thereby, to rapidly produce a pressurized vapor for rapidly ejecting said projectile from said housing.

17. The combination as defined in claim 16 wherein said container includes a hollow cap depending from one side of said container, said cap having a first end wall remote from said side, said line of weakness extending around said cap adjacent said end wall.

18. The combination as defined in claim 17 wherein said container opening means comprises a member mounted within said housing adjacent said cap including a projection extending therefrom and received by said cap and loading means for forcing said projection to abut said first end wall effecting failure of said cap along said line of weakness.

19. The combination as defined in claim 18 wherein said projection includes sealing means circumferentially thereabout to sealingly engage said cap to effect closure of said container when said failure occurs, retraction of said loading means effecting movement of said container away from said projection exposing said liquid to the interior of said housing.

20. The combination as defined in claim 19 wherein said member is fixedly mounted within said housing and wherein said loading means comprises:

(a) an annular slide including a second end wall, said second end wall having a threaded bore axially therethrough,

( b) a piston having an externally threaded shaft extending therefrom, said shaft being received by said bore, said slide and piston being advanced into said housing to a first position with said piston engaging said container for forcing said container onto said projection, rotation of said piston relative to said slide causing said piston to translate away from said slide and causing said first end wall to abut said projection and effect said failure, and

(c) locking means for holding said slide in said first position, release of said locking means subsequent to failure of said cap permitting retraction of said loading means away from said projection.

21. The combination as defined in claim 19 wherein said housing is an elongated cylindrical tube.

22. In launching means for propelling a projectile, wherein a housing means is provided that is adapted to re ceive said projectile and permit substantially unrestrained acceleration thereof, the improvement comprising:

(a) a closed container communicating with the interior of said housing means,

(b) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature, and

() means for rapidly exposing a substantial surface of said liquid to the interior of said housing means to effect flashing of said liquid and thereby to rapidly produce a pressurized vapor for rapidly ejecting said projectile from said housing means.

23. Launching means as defined in claim 22 wherein said housing means is an elongated cylindrical tube.

24. Launching means for propelling a projectile, comprising:

(a) a housing adapted to receive said projectile and permit substantially unrestrained acceleration thereof, (b) a container having a port and a closure means in sealing relationship with said port effecting closure of said container, said port being of size to expose a substantial portion of the interior of said container and being in communication with the interior of said housing,

(0) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature, and

((1) container opening means for rapidly removing said closure means from said port to expose :a substantial surface of said liquid to the interior of said housing to effect flashing of said liquid and thereby to rapidly produce a pressurized vapor for rapidly ejecting said projectile from said housing, said opening means comprising:

(i) extraction means slidably mounted within said housing and attached to said closure means,

(ii) biasing means normally urging said extraction means in a direction to remove said closure means from said port, and

(iii) locking means holding said extraction means in a first position wherein said closure means is in sealing relationship with said port, release of said locking means permitting said biasing means to move said extraction means into a second position effecting removal of said closure means from said port.

25. In combination, a projectile having a predetermined external shape and size, and launching means for propelling said projectile, said launching means comprising:

(a) a housing with a cross sectional dimension substantially the same as that of said projectile for receiving said projectile and permitting substantially unrestrained acceleration thereof,

(b) a closed container communicating with the interior of said housing,

(c) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature, and

(d) means for rapidly exposing a substantial surface of said liquid to the interior of said housing to effect flashing of said liquid and thereby to rapidly produce a pressurized vapor for rapidly ejecting said projectile from said housing.

26. In combination, a projectile having a predetermined external shape and size, and launching means for propelling said projectile, said launching means comprising:

(a) a housing with a cross sectional dimension substantially the same as that of said projectile for receiving said projectile and permitting substantially unrestrained acceleration thereof,

(b) a container having a port and a closure means in sealing relationship with said port effecting closure of said container, said port being of a size to expose a substantial portion of the interior of said container and being in communication with the interior of said housing,

(c) a liquid within said container, said liquid having a boiling point at ambient pressure below the ambient temperature, and

(d) container opening means for rapidly removing said closure means from said port to expose a substantial surface of said liquid to the interior of said housing to effect flashing of said liquid and thereby to rapidly produce a pressurized vapor for rapidly ejecting said projectile from said housing.

(References on following page) References Cited UNITED STATES PATENTS 3,204,625 9/ 1965 Shepherd 124-11 RICHARD C. PINKHAM, Primary Examiner.

Huey 124-11 WILLIAM R. BROWNE, Assistant Examiner. Mahon et a1 222387 5 Schmidt et a1. 222-80 Enfield 12411 62-45; 124-37; 239-337 

